1. Field of the Invention
The present invention relates to a control apparatus for an automatic transmission, which controls the oil pressure for operating the clutch for changing the speed of the automatic transmission of a vehicle, and to a control method.
2. Prior Art
According to a conventional control method of this type as taught in, for example, Japanese Patent Laid-Open No. 25662/1992, the operation oil pressure to be supplied to a friction coupling device has been controlled by learning, so that a deviation decreases between a target value of change in the torque and a practical value at the start of the feedback control operation.
According to the control method taught in Japanese Patent Laid-Open No. 25662/1992, however, the deviation increases due to a change in the opening degree of the throttle and a change in the oil temperature in the automatic transmission, leaving a problem in that the control stability is impaired in the feedback control operation when the speed is being changed.